Lubricant containing alkenyl succinimide and hydroxypolyamine



United States Patent 3,210,283 LUBRICANT CONTAINING ALKENYL SUCCIN- IMIDE AND HYDROXYPOLYAMINE Frank A. Stuart, Orinda, and Robert G. Anderson, Novato, Calif., assignors to California Research Corporation, San Francisco, Calif, a corporation of Delaware No Drawing. Filed June 18, 1963, Ser. No. 288,628 4 Claims. (Cl. 252-515) This application is a continuation-in-part of Frank A. Stuart and Robert G. Anderson, US. application Serial No. 102,366, filed April 12, 1961, now abandoned.

This invention pertains to lubricating oil compositions having incorporated therein the metal-free detergents, alkenyl succinimides, in combination with certain hydroxypolyamines.

Alkenyl succinic anhydrides and numerous derivatives thereof are well known in the art. For example, alkenyl succinic anhydrides in which the alkenyl radical contains from 5 to 20 carbon atoms are taught as corrosion inhibitors in lubricating oil composition. Also products obtained by reacting such alkenyl succinic acid anhydrides with monoamines are taught as ferrous corrosion inhibitors for lubricating oil compositions.

However, the above known alkenyl succinimides are not useful as detergents in lubricating oil compositions. In contrast thereto, the alkenyl succinimides which are described herein are new compounds which are useful as detergents in lubricating oil compositions.

Present day internal combustion engines operate at high speeds and high compression ratios. When used in the so called city stopand-go driving, which includes the greater part of the driving condition for a large percentage of todays automobiles, the internal combustion engines do not reach the most efiicient operating temperatures. Under city driving conditions, large amounts of partial oxidation products are formed, and reach the crankcase of the engine by blowing past the piston rings. Most of these partial oxidation products are oil insoluble, tending to form deposits on the various operating parts of the engine, such as the pistons, piston rings, etc. For the purpose of preventing the deposition of these products on the various engine parts, it is necessary to incorporate detergents in the lubricating oil compositions, thus keeping these polymeric products highly dispersed in a condition unfavorable for deposition on metals.

For the most part, the various detergents which are added to crankcase oils to reduce this formation of sludges and varnishes are metal organic compounds, particularly those compounds wherein the metal is linked to an organic group through an oxygen atom. Although these metal-containing organic compounds have some effectiveness as detergents for dispersing the precursors of deposits within the oil itself rather than permitting them to form added deposits on the engine parts, they have the disadvantage of forming ash deposits in the engine. These ash deposits lower engine performance by fouling spark plugs and valves, and contributing to preignition.

Lubricating oil compositions containing N-substituted polyamine alkenyl succinimides as metal-free detergents are described in Frank A. Stuart, Robert G. Anderson and Alan Y. Drummond copending application Serial No. 835,437, filed August 24, 1959. The addition thereto of certain polyamines markedly improves the effectiveness of such detergents as lubricating oil additives.

It is a particular object of this invention to provide lubricating oil compositions which are compounded with a metal-free detergent in combination with certain hydroxypolyamines.

Therefore, in accordance with this invention, it has been discovered that lubricating oil compositions par- 'ice ticularly useful for heavy-duty service are obtained by incorporating certain hydroxyalkylalkylenepolyamines and N-substituted monoalkenyl succinimides derived from tetraethylene pentamine in oils of lubricating VIS- cosity.

By the use of lubricating oil compositions containing the N-substituted alkenyl succinimides in combination with the hydroxypolyamines as described herein, diesel and gasoline engine parts remain remarkably free of deposits and varnish, even under severe operating conditions.

The monoalkenyl succinimides of tetraethylene pentamine have the formula wherein R is a hydrocarbon radical having a molecular weight from about 400 to about 3000; that is, R is a hydrocarbon radical containing about 30 to about 200 carbon atoms.

The R radical of the above formula, that is, the alkenyl radical, is derived from an olefin containing from 2 to 5 carbon atoms. Thus, the alkenyl radical is obtained by polymerizing an olefin containing from 2 to 5 carbon atoms to form a hydrocarbon having a molecular weight ranging from about 400 to about 3000, more preferably, 900 to 1200. Such olefins are exemplified by ethylene, propylene, l-butene, 2-butene, isobutene, and mixtures thereof. Since the methods of polymerizing the olefins to form polymers thereof is immaterial in the formation of the new compound described herein, any of the numerous processes available can be used therefor.

These alkenyl succinimides of tetraethylene pentamine can be prepared by reacting maleic anhydride with an olefinic hydrocarbon, followed by reacting the resulting alkenyl succinic anhydride with tetraethylene pentamine.

The reaction between a polyolefin and maleic anhydride is an uncatalyzed addition reaction which should not be confused with a copolymerization reaction such as that obtained with a vinyl monomer and maleic anhydride. This reaction can proceed in a mole ratio of the polyolefin to the maleic anhydride of 1:1 to 1:10, preferably from 1:1 to 1:5. The reaction temperature can vary from 300 F. to 450 F. Because of the greater yield of products obtained thereby, it is preferred to use the high range of temperatures (e.g., 375 F. to 450 F.).

In the reaction between an alkenyl succinic acid anhydride and tetraethylene pentamine, in which reaction the temperatures are from 220 F. to 500 F., preferably from 300 F. to 400 F., the yield of the imide is extremely high even though the reactants are used in equal molar ratios. This is surprising, since under the conditions of the reaction there is an excess of secondary amino groups, and any reaction with the secondary amino groups would lead to amide formation; thus preventing imide formation.

Since the reaction between the polyolefin and maleic anhydride may not go to completion, the resulting alkenyl succinic anhydride may contain some unreacted polyolefin. As it may not be desirable to separate out this unreacted polyolefin at this stage, the resulting imide formed by reaction of the alkenyl succinic anhydride and the diamine will contain this polyolefin as an impurity which can be a diluent in the formation of lubricating oil compositions. However, if it is so desired, this unreacted polyolefin can be removed by precipitation, for example, by acetone or methanol from a hydrocarbon solution.

The particular hydroxyalkylalkylenepolyamines which are effective herein in combination with alkenyl succinimides of tetraethylene pentamine are of the formula reaction mixture was cooled to 150 F. and 700 cc. of hexane added; after which the mixture was filtered under vacuum. After vacuum distillation to remove the hexane from the filtrate, the product was maintained at 350 F. at an absolute pressure of 10 mm. Hg for one hour to mole ratio is from 3:1 to 100:1, preferably from 10:1 to 65 The preparation of the alkenyl succinimidcs of tetraalkylene pentamine is illustrated in the following examples.

EXAMPLE I.PREPARATION OF POLYBUTENYL SUCCINIC ANHYDRIDE L 5 remove traces of maleic anhydride. The crude poly- Whfiftiin n iS a num er frOm 0 t0 1, and q is a number butenyl succinic anhydride thus prepared had a saponificafrom 1 to 10. tion umber of 79. The particular polyamines are exemplified as follows: EXAMPLE 2 PREPARATION OF TETRAETHYL hydroxyethylethylene diamine, hydroxyethyldiethylene ENE PENTJAMINE DERIVATIVE OF THE POLY triamine, hydroxyethyltetraethylene pentamine, hydroxy- .BUTENYL SUCCINIC NH DRIDE OE EXAMPLE ethylnonaethylene decamine, etc. 1 HEREIN ABOVE Lubricating oils which can be used as base oils include a wide variety of lubricating oils, such as naphthenic base, A mixture of 84 g. (0.45 mole) of tetraethylene penparaflin base, and mixed base lubricating oils, other hytamine and 702 g. (0.45 mole) of the polybutenyl sucdrocarbon lubricants, e.g., lubricating oils derived from cinic anhydride of Example 1 hereinabove, was blended coal products, and synthetic oils, e.g., alkylene polymers with agitation at 125 F. in a nitrogen atmosphere. The (such as polymers of propylene, butylene, etc., and the temperature was increased to 400 F. during a period of mixtures thereof), alkylene oxide-type polymers (e.g., one hour, after which the absolute pressure was reduced propylene oxide polymers) and derivatives, including alto about 200 mm. Hg during a period of 30 minutes to kylene oxide polymers prepared by polymerizing the alkylfacilitate the removal of water. The reaction mixture ene oxide in the presence of water or alcohols, e.g., ethyl was then allowed to reach room temperature at this realcohol, dicarboxylic acid esters (such as those which are duced pressure. The reaction product contained 5.1% prepared by esterifying such dicarboxylic acids as adipic nitrogen (theory=5.4%). Infra-red analysis showed acid, azelaic acid, suberic acid, sebacic acid, alkanol sucthat the reaction product was an imide containing a polycinic acid, fumaric acid, maleic acid, etc., with alcohols butene side chain. such as butyl alcohol, hexyl alcohol, 2-ethylhexyl alcohol, The alkenyl succinimides described herein are more dodecyl alcohol, etc.), liquid esters of acids of phosphorus, effective as detergents than alkenyl succinimides having alkyl benzenes (e.g., monoalkyl benzene such as dodecyl fewer nitrogen atoms in the amine portion of the molebenzene, tetradecyl benzene, etc.) and dialkyl benzenes cule, and more efiective than succinimides having less than (e.g., non-nonyl 2-ethylhexyl benzenes); polyphenyls (e.g., 30 carbon atoms in the alkenyl radical. The use of amyl biphenyls and terphenyls), alkyl biphenyl ethers, polymers amine, for example, in place of tetraethylene pentamine of silicon [e.g., tetraethyl silicate, tetraisopropyl silicate, in the preparation of the succinimide, results in a prodtetra(4-methyl-2-tetraethyl) silicate, hexyl(4-rnethyl-2- uct which is ineffective as a detergent in lubricating oil pentoxy) disiloxane, poly(methyl) siloxane, poly(methylcompositions. phenyl) siloxane], etc. Synthetic oils of the alkylene ox- Table I hereinbelow presents data obtained with lubriide-type polymers which may be used include those exemcating oil compositions containing the combination of plified by the alkylene oxide polymers. hydroxyalkylalkylenepolyamines and N-substituted mono- The above base oils may be used individually or in comalkenyl succinimides derived from tetraethylene pentbinations thereof, wherever miscible or wherever made so amine. by the use of mutual solvents. The monoalkenyl succinimide used was an N-sub- The alkenyl succinimides of tetraalkylene pentamine stitutedsuccinimide derived from tetraethylene pentamine can be used in oils of lubricating viscosity as described wherein the alkenyl radical had a molecular weight of herein in amounts of 0.1% to by weight, preferably about 1000, which alkenyl radical was a polymer of iso- 0.25% to 5%, by weight. 45 butene.

The polyamines can be used in amounts of 0.01% The tests were made in a Caterpillar L-1 engine acto 2%, by weight, preferably 0.02% to 0.5% by weight. cording to Supplement I conditions for a period of It is preferred that the succinimide and the polyamine hours as described in the Coordinating Research Council be used in amounts such that the succinimide/polyamine Handbook, January 1946.

Table l A B O D E F G H Additive, wt. percent:

succinimide 0. 0 1. 0 0. U 1. 0 1. 0 1. 0 1. 0 1. 0

Diethylene triamine 0. 0 O. 051 0. 051

Tetraethylene pentarnine 0.0 0.10

Hydroxyethylethylene diarnine 0. 0 0. 078 Diethylene triamine monoacetate 0.0 0. 122

Dodecylarnine 0.0 0.278 Test results:

P.D.N0 800,800,800 280, 00, 120 340,130,40 0, 0,0 125,105,130 70, 0,0 55,10,30 610, 330, 25

The PD. Nos. refer to the piston discoloration rating. After the engine test, the three piston lands are examined visually. To a piston skirt which is completely black is assigned a PD. number of 800; to one which is completely clean, a PD. number of 0; to those intermediate between completely black and completely clean are assigned P.D. numbers intermediate in proportion to the extent and degree of darkening.

The base oils were California SAE 30 base oils.

It is readily seen from the data set forth hereinabove in Table I that lubricating oil compositions containing the combination. of the above-defined hydroxypolyamines and alkenyl succinimides of tetraethylene pentamine as described herein are superior as lubricating oil compositions for the lubricating of internal combustion engines to the compositions containing only the alkenyl succinimides of tetraethylene pentamine. On the other hand, it is noted that monoamines, for example, dodecylamine, have a detrimental effect on the described succinimides as ashless detergents in lubricating oil compositions.

In addition to the compositions described hereinabove, lubricating oil compositions may also contain other detergents, viscosity index improving agents, rust inhibitors, oiliness agents, grease thickening agents, etc.

We claim:

1. A lubricating oil composition comprising a major proportion of an oil of lubricating viscosity, from 0.1 to 45 percent by weight of an alkenyl succinimide of tetraethylene pcntamine having the following formula:

wherein R is a hydrocarbon radical containing from 30 to about 200 carbon atoms, and from 0101 percent to 2 percent by weight of a hydroxypolyamine of the formula:

wherein n is a number from 0 to 1, and q is a number from 1 to 10, wherein the succinimide/polyamine mol ratio is from :1 to 75:1.

2. A lubricating oil composition comprising a major proportion of an oil of lubricating viscosity and from 0.25 to 5 percent by weight of an alkenyl succinimide of tetraethylene pentamine having the following formula:

wherein R is a hydrocarbon radical containing from 30 to about 200 carbon atoms, and from 0.2 percent to 0.5 percent by weight of a hydroxypolyamine of the formula:

wherein R is a polymer of isobutene having a molecular Weight of about 1,000, and from 0.02 percent to 0.5 percent by weight of N-( 2-hydroxyethyl) ethylene diamine.

4. A lubricating oil composition comprising a major proportion of an oil of lubricating viscosity, from 0.1 percent to 45 percent by weight of an alkenyl succinimide of tetraethylene pentamine having the following formula:

wherein R is an hydrocarbon radical containing from 30 to about 200 carbon atoms, and from 0.01 percent to 2 percent by Weight of N-(2-hydroxyethyl)ethylene di amine, wherein the succinimide/diamine mol ratio is from 10:1 to :1.

References Cited by the Examiner UNITED STATES PATENTS 2,318,729 5/43 Wilson 260584 X 2,680,137 6/54 Pickett et al. 260-584 2,767,214 10/56 Bersworth 260584 3,131,150 4/64 Stuart et al 252-34.7

DANIEL E. WYMAN, Primary Examiner. 

1. A LUBRICATING OIL COMPOSITION COMPRISING A MAJOR PROPORTION OF AN OIL OF LUBRICATING VISCOSITY, FROM 0.1 TO 45 PERCENT BY WEIGHT OF AN ALKENYL SUCCINIMIDE OF TETRAETHYLENE PENTAMINE HAVING THE FOLLOWING FORMULA: 